Known domestic, electric water heaters have a water tank with a cold water inlet near the bottom of the tank and a hot water outlet near the top of the tank. An internal heating element is positioned near the bottom of the tank. This arrangement has several disadvantages.
Firstly, the entire volume of water in the tank must be heated from bottom to top in order to provide hot water at the outlet, which is not energy efficient.
Secondly, much care must be taken when admitting fresh cold water to the tank so as not to disturb the rising segments of heated water. This normally requires the use of, for example, diffusers to slow the rate of cold water entering the tank, which adds to the complexity and cost of the water heater. This problem is exacerbated if, for example, the electric water heater tank is connected in parallel with a solar water heater.
It is an object of the present invention to substantially overcome or at least ameliorate one or more of the prior art deficiencies.